Method and apparatus for removal of soot from lubricating oil

ABSTRACT

A method for removing soot, sludge and other insoluble particulates from an engine oil is provided, the method comprising: disposing an oil containing the particulates between a pair of electrodes, wherein one of the electrodes is a positive electrode; applying a coating to the surface of the positive electrode, wherein the coating is configured to collect a portion of the particulates on the positive electrode; applying a current to the electrodes for a period of time, wherein portions of the particulates agglomerate on the positive electrode and other portions of the particulates not collected on the positive electrode are preagglomerated resulting in a larger average particle size; and applying a filtering process to remove the particulates not collected on the positive electrode. Also, disclosed herein is a filter for removing soot, sludge and other insoluble particulates from an engine oil.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication

Ser. No. 61/108,632 filed Oct. 27, 2008 the contents of which areincorporated herein by reference thereto.

TECHNICAL FIELD

This application relates to an apparatus and method for removing soot,sludge and other insoluble particulates from lubricating oils, and moreparticularly this application relates to particulate removal through theuse of electro-agglomeration.

BACKGROUND

In modern automobiles, many types of fluid filters are common. An oilfilter is a fluid filter used to strain the oil in the engine thusremoving abrasive particles. Most such filters use a mechanical or‘screening’ type of filtration, with a replaceable cartridge having aporous filter element therein, through which oil is repeatedly cycled toremove impurities such as small particles or dirt and metal. “Dirty” oilenters an oil filter under pressure, passes through the filter mediawhere it is “cleaned,” and then is redistributed throughout the engine.This can prevent premature wear by ensuring that impurities will notcirculate through the engine and reach the close fitting engine parts.Filtering also increases the usable life of the oil.

It is common for the normal operation of an internal combustion engineparticularly that of a diesel engine, to result in the formation ofcontaminants. These contaminants include, among others, soot, which isformed from incomplete combustion of the fossil fuel, and acids thatresult from combustion. Both of these contaminants are typicallyintroduced into the lubricating oil during engine operation and tend toincrease oil viscosity and generate unwanted engine deposits, leading toincreased engine wear.

The conventional solution to these problems has been to place variousadditives into lubricating oils, during their initial formulation. Inorder to combat soot-related problems, many conventional lubricatingoils include dispersants that resist agglomeration of soot therein.These work well for a short period, but may become depleted.Additionally, and due to the solubility and chemical stability limits ofthese dispersants in the oil, the service lives of the lubricating oiland the oil filter are less than optimal.

In order to counteract the effects of acidic combustion products, manyconventional motor oils include neutralizing additives known asover-based detergents. These are a source of TBN (total base number),which is a measure of the quantity of the over-based detergent in theoil, expressed in terms of the equivalent number of milligrams ofpotassium hydroxide that is required to neutralize all basicconstituents present in 1 gram of sample. Higher TBN oils provide longerlasting acid neutralization. The depletion of TBN is an importantlimiting factor for many internal combustion engines, and in particularfor heavy-duty applications with diesel engines.

In order to improve engine protection and to combat other problems,conventional lubricating oils often include one or more furtheradditives, which may be corrosion inhibitors, antioxidants, frictionmodifiers, pour point depressants, detergents, viscosity indeximprovers, anti-wear agents, and/or extreme pressure additives. Theinclusion of these further additives may be beneficial; however, withconventional methods, the amount and concentration of these additivesare limited by the ability of lubricating oils to suspend theseadditives, as well as by the chemical stability of these additives inthe oil.

In addition to trapping impurities and decontaminating oil, it is therole of the oil filter to ensure fast and efficient flow through itsmedia. Oil is the life blood of an engine, and its constant flow isessential for proper lubrication of engine components and the preventionof friction, heat and wear. Engine components rely on the oilcirculation system to deliver a steady and adequate supply of motor oil.

Accordingly, it is desirable to provide a method and apparatus forremoving the oil soot, sludge and other insoluble particulates from theoil.

SUMMARY

Disclosed herein is an apparatus and method for removing soot, sludgeand other insoluble particulates from the engine oil. In one exemplaryembodiment, a method for removing the particulates from an engine oil isprovided, the method comprising: disposing an oil containing theparticulates between a pair of electrodes, wherein one of the electrodesis a positive electrode; applying a coating to the surface of thepositive electrode, wherein the coating is configured to collect aportion of the particulates on the positive electrode; applying a anelectric current to the electrodes for a period of time, whereinportions of the particulates agglomerate on the positive electrode andthe positive electrode is removed thereby removing the particulates fromthe oil.

In another exemplary embodiment, a method for removing particulates froman engine oil is provided, the method comprising: disposing an oilcontaining soot between a pair of electrodes, wherein one of theelectrodes is a positive electrode; applying a coating to the surface ofthe positive electrode, wherein the coating is configured to collect aportion of the soot particles on the positive electrode; applying anelectric current to the electrodes for a period of time, whereinportions of the soot agglomerate on the positive electrode and otherportions of the soot not collected on the positive electrode ispreagglomerated resulting in a larger average particle size; andapplying a centrifugal force to the oil to remove the soot.

In another exemplary embodiment, a method for removing soot from engineoil is provided, the method comprising: disposing an oil containing sootparticles between a pair of electrodes, wherein one of the electrodes isa positive electrode; applying a coating to the surface of the positiveelectrode, wherein the coating is configured to collect a portion of thesoot particles on the positive electrode; applying a direct current tothe electrodes for a period of time to generate an electric field,wherein the electric field causes a portion of the soot particles toagglomerate on the positive electrode; and removing the positiveelectrode and the portion of soot particles agglomerated on the positiveelectrode to reduce the amount of soot particles in the oil.

In another exemplary embodiment a method for removing soot from engineoil is provided, the method comprising: disposing an oil containing sootparticles between a pair of electrodes; applying a DC or AC current tothe pair of electrodes for a period of time to generate an electricfield, wherein the electric field causes the soot particles toagglomerate resulting in a larger average particle size of the sootparticles; and removing the soot particles by a filtering process,wherein the filtering process comprises application of a centrifugalforce to the oil, wherein the soot particles are disposed upon a surfacethat is removable from the oil.

In another exemplary embodiment a filter for removing soot particlesfrom an engine oil having soot particles disposed therein is provided,the filter comprising: a housing having an inlet and an outlet defininga flow path through a chamber defined by the housing; a pair ofelectrodes disposed in the flow path, the pair of electrodes beingelectrically coupled to a direct current, wherein an electric field isgenerated by the pair of electrodes and one of the pair of electrodes isa positive electrode, wherein the electric field causes a portion of thesoot particles to agglomerate on the positive electrode, wherein atleast the positive electrode is removable from the filter to allowremoval of the soot particles agglomerated on the positive electrode;and a coating applied to the surface of the positive electrode, whereinthe coating is configured to improve the collecting efficiency of theagglomerated portion of soot particles on the positive electrode.

In another exemplary embodiment a filter for removing soot particlesfrom an engine oil having soot particles disposed therein is provided,the filter comprising: a housing having an inlet and an outlet defininga flow path through a chamber defined by the housing; a pair ofelectrodes disposed in the flow path, the pair of electrodes beingelectrically coupled to an AC current, wherein an electric field isgenerated by the pair of electrodes and wherein the electric fieldcauses a portion of the soot particles to agglomerate resulting in alarger average particle size of the soot particles and some of the sootparticles are removed by a filtering process, wherein the filter furthercomprises a rotatable member capable of applying a centrifugal force tothe oil and the filtering process comprises application of a centrifugalforce to the oil, wherein soot particles are disposed upon a surface ofthe rotatable member that is removable from the oil.

The above-described and other features and advantages of the presentapplication will be appreciated and understood by those skilled in theart from the following detailed description, drawings, and appendedclaims.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1 and 2 illustrate a pair of electrodes and a particulateagglomeration process;

FIG. 3 is a graph illustrating the effect of the electric field on thecentrifugal sedimentation of used oil;

FIG. 4 is a graph illustrating the effect of the electric field on thesoot level of used oil;

FIG. 5 is a graph illustrating the effect of electro-agglomeration onthe TBN of an oil;

FIG. 6 is a graph illustrating the time course of electro-agglomeration;

FIG. 7 is a graph illustrating the soot removal and electrode sootloading of used oil in accordance with an exemplary embodiment of thepresent invention;

FIG. 8 is a schematic illustration of a filter constructed in accordancewith an exemplary embodiment of the present invention;

FIG. 9 is a schematic illustration of a filter constructed in accordancewith an alternative exemplary embodiment of the present invention;

FIG. 10 is a schematic illustration of a filter constructed inaccordance with yet another alternative exemplary embodiment of thepresent invention;

FIG. 11 is a schematic illustration of a filter constructed inaccordance with yet another alternative exemplary embodiment of thepresent invention;

FIG. 12 is a schematic illustration of a filter constructed inaccordance with still another alternative exemplary embodiment of thepresent invention;

FIG. 13 is a schematic illustration of a filter constructed inaccordance with yet another alternative exemplary embodiment of thepresent invention;

FIG. 13A is a schematic illustration of a filter system constructed inaccordance with yet another alternative exemplary embodiment of thepresent invention;

FIG. 14 is a cross sectional view of a filter constructed in accordancewith an exemplary embodiment of the present invention;

FIG. 15 is a cross sectional view of a filter constructed in accordancewith an alternative exemplary embodiment of the present invention; and

FIG. 16 is a partial cross-sectional view of the filter illustrated inFIG. 15.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

A disadvantage to the use of centrifugal methods for soot and/orparticulate removal is the relatively low efficiency as currentlypracticed. In accordance with an exemplary embodiment of the presentinvention methods and apparatus for soot, sludge and other insolubleparticulates from an oil are provided. Non-limiting embodiments aredirected to an oil filtration device (e.g., filter) that is configuredto apply an electric field in accordance with an exemplary embodiment ofthe present invention. One non-limiting example of such an oilfiltration device is found in U.S. patent application Ser. No.11/854,295 filed Sep. 12, 2007, the contents of which are incorporatedherein by reference thereto. Thereafter, the agglomerated soot and/orother particulates are removed via removal of a particulate-coveredelectrode, application of a centrifugal force, and/or subsequentfiltration by a filtration media. In accordance with an exemplaryembodiment, any one of the three methods may be employed alone or incombination with one another.

In accordance with an exemplary embodiment of the present invention, theapplication of a strong electric field to the oil will cause particulateagglomeration, thereby enhancing subsequent removal by centrifugation orother separation techniques. In one exemplary embodiment, the separationtechniques may employ subsequent filtration using a filtration media,removal of an electrode or electrodes, that apply the electric fieldwhen particulates have agglomerated or adhered to the electrode itselfor any combination of the foregoing processes. In accordance with anexemplary embodiment, the process of electro-agglomeration will causethe average soot particulate or other particulate size to increase. Thiswill cause an increase of the sedimentation or collection rate uponapplication of a centrifugal force or other filtration technique.

In accordance with an exemplary embodiment, the lubricating oilcontaining soot, sludge and other insoluble particulates is positionedbetween two electrodes connected to a DC power supply. A direct currentof up to 5 kV is applied to the electrodes. Of course, currents greateror less than 5 kV may be used. The resulting strong electrical fieldwill cause the soot, sludge and other insoluble particulates from theoil to agglomerate on the positive electrode. To enhance particulateagglomeration, a coating is applied to the surface of the positiveelectrode, wherein the coating is a soot-collecting agent havingproperties and configured to improve the collecting efficiency of theagglomerated soot or other particles on the positive electrode. Theagglomerated particles may then be actively removed. In one exemplaryembodiment, the positive electrode with the agglomerated particles maybe simply removed and this electrode is either discarded or cleaned. Anew electrode, or the cleaned electrode, is replaced into the oilfiltration device which, in one embodiment, may comprise an oil filtermounted on an internal combustion engine, for example a diesel engine,wherein soot removal from the oil is desirable.

In another exemplary embodiment and by simply removing the electricfield a partial or passive deagglomeration may result, wherein thepartially agglomerated particulates will then be separated from theliquid oil phase by centrifugation or other separation method, which mayinclude filtration through filtration media.

In accordance with an exemplary embodiment, a voltage potential isapplied to electrodes connected to an electric power supply. In onenon-limiting example, a voltage potential of up to 5 kV or less isapplied to the electrodes. Of course, voltage potentials greater or lessthan 5 kV may be used. The strong electric field will cause the soot toagglomerate on the positive electrode. To enhance soot or other particleagglomeration, a coating is applied to the surface of the positiveelectrode, wherein the coating is a soot-collecting agent havingproperties and configured to improve the collecting efficiency of theagglomerated of soot particles on the positive electrode. This approachcan serve as an effective means of reducing the soot level in thecirculating oil and entails no further purification or post separationscheme. However, a portion of the soot or other particulates remainingin the liquid phase that is not collected on the electrode has beendemonstrated to be preagglomerated resulting in a larger averageparticle size or diameter. This larger average particle diameter allowsfor the particulates to be more efficiently trapped by a filtrationmedia of a filter disposed in a flow path of a filter constructed inaccordance with the teachings of exemplary embodiments of the presentinvention.

Also, and in some instances, no agglomeration on the electrode isobserved if the applied voltage is alternating in nature, howeveragglomeration does occur in the circulating oil. The partiallyagglomerated or preagglomerated soot not collected on the electrode canthen be separated from the liquid oil phase by centrifugation or otherdownstream separation method.

The attached Figures illustrate various exemplary embodiments of thepresent invention. In one embodiment, and upon exposure to a strongelectrical field, particles will pre-agglomerate or clump prior to orduring a process of migration to the positive electrode. This willresult in larger average particle size and would likely increasesedimentation and collection rate of the particles.

FIGS. 1 and 2 illustrate a pair of electrodes 10 and 12. Also shown area plurality of soot particles 14. In accordance with an exemplaryembodiment of the present invention and wherein an electrical field isgenerated by the pair of electrodes, soot particles 14 agglomerate intoa mass of soot particles 16 shown in FIG. 1. Although soot particles 14are shown it is also understood that exemplary embodiments of thepresent invention contemplate electro-agglomeration of other particlessuch as sludge and other insoluble particulates. Furthermore, the massof soot particles is then attracted towards the positive electrode 10shown as adhered particle 18. Alternatively and as shown in FIG. 2, thesoot particles may agglomerate directly onto the positive electrode 10to provide agglomerated particle 18 on the positive electrode. Forexample, the soot particles acquire charge and migrate to the positive(+) electrode in a one-by one fashion. The electrode includes a coatingwhich is applied to the surface, wherein the coating is asoot-collecting agent having properties and configured to improve thesoot-collecting efficiency on the surface of the positive electrode. Inone exemplary embodiment, the electrodes are removably placed within afilter housing in fluid communication with an oil flow and as thepositive electrode is loaded with soot the same can be removed andreplaced as necessary. As will be discussed herein the filter may be abypass filter or the electrodes may comprise part of a filter havingother separation components (e.g., media and/or a centrifuge) or thefilter comprising the electrodes is a part of a series of filterswherein the first filter comprises the electrodes and the subsequentfilters contain the other separation components (e.g., media and/or acentrifuge).

In one alternative embodiment and for separation by filtration, thismechanism would likely require the use of alternating current in orderto maintain agglomerates in the oil flow for downstream separation bycentrifugation.

In accordance with an exemplary embodiment of the present invention theeffect of electro-agglomeration was studied on centrifuge separation,soot levels over time and TBN.

In a first example a time-base study of the effect of an electric fieldon a sedimentation rate was performed wherein electrode soot loadingswere observed.

Example I Electro-Agglomeration

Effect of electric field on centrifugal sedimentation rate   15,000 RPMat 25 C.   25,000 RPM at 40 C.   Change in equipment setup   Time-basestudy of effect of electric field on   sedimentation rateElectro-agglomeration-Effect on Centrifugal Sedimentation Power Supply  Hipotronics HD125 AC/DC Power Supply   25 kV/5 mA (adjustable) outputcurrent-set to 15 kV (DC) Electrodes   60 × 60 mesh screen, 1 cm × 5.2cm (w × l), spaced 1.5 cm apart Oil   (~6.9 wt % soot) PROTOCOL  Electrodes clamped vertically in 10 cc flask containing ~10 cc used  oil, no mixing   Applied 15 kV voltage for 90 minutes   2-3 g ofelectro-treated oil removed immediately and centrifuged:     15,000 rpmat 25 C. for 1 hour     25,000 rpm at 40 C. for 1 hour   Soot by TGAperformed on spun and unspun electro-treated oil and   control oil FIG.3 illustrates the electro-agglomeration effect on centrifugalsedimentation.   Electric field (DC) treatment had no effect onsedimentation rate at   15,000 RPM and 25 C.   Spinning hotter andfaster showed at least 2X differentiation   Appears that the soot does‘preagglomerate’ to some extent prior to   settling on electrode

Example II Electro-Agglomeration

Change in Setup   Same power supply   Changed electrodes from 60 × 60mesh screen, 1 cm × 5.2 cm   (w × l), spaced 1.5 cm apart to platinumgauze 0.8 cm × 1.9 cm,   same spacing, with platinum wire terminals  This change will allow manual switching of current polarity for  frequencies other than 60 Hz AC Current   Power supply has built-in ACmode at 60 Hz   Lower frequency work will be done manually(cycles/minute) Effect of time on centrifugal sedimentation rate  Previous work done at fixed 90 minutes exposure to current (15 kV)  0.5, 1.0 and 1.5 Hrs exposure to 15 kV using new setupElectro-agglomeration-Effect on Soot Level Power Supply   HipotronicsHD125 AC/DC Power Supply   25 kV/5 mA (adjustable) output current-set to15 kV (DC) Electrodes   60 × 60 mesh screen, 1 cm × 5.2 cm (w × l),spaced 1.5 cm apart Oil   (~6.9 wt % soot) PROTOCOL   Electrodes clampedvertically in 10 cc flask containing ~9.5 cc used   oil, no mixing  Applied 15 kV voltage and noted current decrease over time   0.25 ccsamples removed at 0, 0.5, 1, 2, 4 and 8 hours for soot TGA   analysis

FIG. 4 illustrates the electro-agglomeration of soot vs. time forExample II. As shown, the soot levels decreased substantially over aperiod of several hours. Also, the agglomerated gel/paste on theelectrode contained >24 wt % soot. Also, the soot concentrated by ˜4× inoil matrix and the current dropped off rapidly with build-up of theagglomerate on the positive electrode.

Example III Electro-Agglomeration—Effect on TBN

Power Supply   Hipotronics HD125 AC/DC Power Supply   25 kV/5 mA(adjustable) output current-set to 15 kV (DC) Electrodes   60 × 60 meshscreen, 1 cm × 5.2 cm (w × l), spaced 1.5 cm apart Oil   (~6.9 wt %soot) PROTOCOL   Electrodes clamped vertically in 25 cc flask containing~20 cc used   oil, no mixing   Applied 15 kV voltage and noted currentdecrease over time   0.75 cc samples removed at 0, 1, 2, 4 and 6.5 hoursfor TBN (D4739)

The effect of electro-agglomeration on TBN is illustrated in FIG. 5, andas shown, little measurable effect on TBN was observed.

Example III Electro-Agglomeration—Effect on Centrifugal Sedimentation

Power Supply   Hipotronics HD125 AC/DC Power Supply   25 kV/5 mA(adjustable) output current-set to 15 kV (DC) Electrodes   Platinumgauze 0.8 cm × 1.9 cm, spaced 1.5 cm apart Oil   From engine test (~6.6wt % soot) PROTOCOL   Electrodes clamped vertically in 20 cc flaskcontaining ~20 cc used   oil, no mixing   Applied 15 kV voltage for 30,60 and 90 minutes   2 cc of electro-treated oil removed and centrifugedat 25,000 rpm,   40 C. for 1 hour   Soot by TGA performed on spun andunspun electro-treated oils and   control oil

FIG. 6 illustrates a time course of electro-agglomeration for ExampleIII. Here the treatments are shown as follows: electric field only inlighter shade and electric field+centrifugation in darker shade. Thevalues above each bar show percent reduction from respective time=0control. At 90 minutes electric field treatment resulted in twice thesoot reduction vs. 30 minutes.

Example IV Electro-Agglomeration—Effect on Centrifugal Sedimentation

Power Supply   Hipotronics HD125 AC/DC Power Supply   25 kV/5 mA(adjustable) output current-set to 15 kV (DC) Electrodes   60 × 60 meshscreen, 1 cm × 5.2 cm (w × l), spaced 1.5 cm apart Oil   (~6.9 wt %soot) PROTOCOL   Electrodes clamped vertically in 10 cc flask containing~10 cc used   oil, no mixing   Applied 15 kV voltage for 90 minutes   3g of electro-treated oil removed immediately and centrifuged   15,000rpm at 25 C. for 1 hour   24,000 g, fluid column height ~1.1 inches  Soot by TGA performed on spun and unspun electro-treated oil and  control oil

FIG. 7 illustrates how much electrode area would be required to reducesoot from 6.5 wt % soot to 2.5 wt % in 10 gallons of oil. 10 gal.oil=32173 g×0.04=1287 g soot and if we use 0.23 g/cm² as max sootloading, then you would need: 1287/0.23=5595 cm² electrode face area orthis would be an electrode screen of about ˜75×75 cm.

Referring in particular to FIG. 8 a non-limiting exemplary embodiment ofthe present invention is illustrated. Here a filter 30 for removing sootparticles from an engine oil having soot particles disposed therein isillustrated schematically. The filter includes a housing 32 having aninlet and an outlet defining a flow path through a chamber 33 defined bythe housing. The flow path is illustrated schematically by arrows 34 andit is, of course, understood that the filter may comprise constructionsor configurations alternative to those shown in the attached Figures asthe same are merely provided as an illustrative example namely, that thefilter has at least one inlet opening to receive unfiltered oil and anoil outlet opening to release oil after it has passed through and/or bythe pair of electrodes. As shown, the pair of electrodes 10 and 12 iselectrically connected to a power supply 36. In accordance with anexemplary embodiment of the present invention and wherein anelectrostatic field is generated by the pair of electrodes, sootparticles 14 agglomerate into a mass or masses of soot particles 18 onthe positive electrode as shown in FIG. 8. Here, to enhance thecapability of the electrode a coating 11 is applied to the surfacethereof, wherein the coating is a soot-collecting agent havingproperties and configured to improve the soot-collecting efficiencythereof.

In accordance with an exemplary embodiment of the present invention thecoating 11 applied to the surface of the positive electrode may includeas components, soot particles extracted from lubricating oil, carbonblack from acetylene, soot purchased commercially, activated carbonpowder, oil-absorbing polymer, other soot-collecting agents or acombination thereof. Here, the coating is adhered to the surface of thepositive electrode using a suitable adhesive material or the like.

In accordance with an exemplary embodiment of the present invention thefilter housing is configured to allow removal and replacement of atleast the positive electrode. For example, the housing may comprise aremovable cap to access the chamber. In one embodiment, the positiveelectrode is removable for cleaning and replacement or it is removed anddiscarded while a new positive electrode is inserted into the filterwherein the new positive electrode is easily coupled to the powersupply. In one exemplary embodiment, the power supply is integral withthe engine or system the oil filter is fluidly coupled to. Furthermore,the power supply can be easily connected and disconnected from thefilter housing and/or the electrodes to allow removal and replacement ofthe filter and/or the positive electrode. In one exemplary embodiment,the filter and housing may be totally removed and replaced or the filterhousing is integral with the engine and comprises a cap for access intothe chamber of the housing, wherein the electrode(s) are removed. Also,and as discussed above, as the soot agglomerates on the positiveelectrode the current levels decrease. Measurement of the current via anamp meter may help to determine when to remove and replace the positiveelectrode namely, the observed current will indicate when the filterneeds to be replaced.

In one alternative embodiment and for separation by filtration via afilter media only, this mechanism would likely require the use ofalternating current in order to maintain agglomerates in the oil flowfor downstream separation by centrifugation or filtration by a filtermedia. Alternatively, and with a DC current the filter media can beemployed to capture soot particles not captured on the positiveelectrode.

In one alternative exemplary embodiment, and as illustrated by thedashed lines in FIG. 8, a mechanical filter element 38 is also disposedinside the filter housing in the flow path 34 of the oil and themechanical filter element is configured to filter the engine oil priorto its flowing out of the filter 30. As will be discussed herein themechanical filter element 38 may be disposed in the same housing 32 ofthe filter with the pair of electrodes 10, 12 or the mechanical filterelement comprising the filter media may be in a separate housing influid communication with the housing containing the pair of electrodes.In either scenario the pair of electrodes 10, 12 will be disposed in theoil flow path 34 after the inlet opening but upstream of a filtrationsurface of the mechanical filter element. This placement will ensurethat the larger sized agglomerated particles will be captured by thefilter media or, in the alternative, a centrifuge device. Alternatively,only the positive electrode is disposed before an exterior filtrationsurface of the mechanical filter element. It is, of course, understoodthat the electrodes may comprise any arrangement as long as the desiredaffects of the electrical field are achieved. In accordance with anexemplary embodiment in order to remove the agglomerated soot particlesat least the positive electrode is removable from the filter, whereinthe positive electrode is either removed and replaced or cleaned andreplaced. It is also understood that the other electrode may also beremovable. Alternatively, the electrodes may be fixed in a removablefilter comprising a housing removably secured to an oil circuit thus,they are not removable from the filter housing and simply accumulatesoot on the positive electrode until the filter or filter housingcomprising the electrodes needs to be replaced. For example, and in oneembodiment, the filter comprising the housing is a screw on type offilter wherein the entire housing comprising the electrodes is removedand replaced. Alternatively and when the housing is integral with theengine, the housing has a cap portion that is removed and the electrodesare simply removed and, if applicable, the filter media is also removed.

Referring in particular to FIG. 9 another non-limiting exemplaryembodiment of the present invention is illustrated schematically. Inaccordance with an exemplary embodiment the electric field also causesthe soot, sludge and other insoluble particulates from the oil toagglomerate resulting in a larger average particle diameter or sizewherein these particles are removed by a filtering process, which may ormay not include the removable positive electrode. In other words, theelectrodes are used to increase the particle size and thereafter theenlarged particle is removed using other filtration techniques (e.g.,centrifugal force or mechanical filtering).

In one alternative exemplary embodiment, and as illustrated by thedashed lines in FIG. 9, a mechanical filter element 38 is disposedinside the filter housing in the oil flow path 34 and it is configuredto filter the engine oil prior to its exiting the filter 30.

In another alternative embodiment, also shown in FIG. 9, the filterfurther comprises a rotatable member 40 capable of applying acentrifugal force 42 to the oil 40 & 42. The centrifugal force causesthe soot particles 14 to be disposed upon a surface of the rotatablemember (e.g., a mesh screen or other filtration media), which is alsoremovable from the filter to allow for removal of the particles. Thisfilter may comprise the pair of electrodes, the filter media and therotatable member or any combination thereof. In this embodiment, a motoror oil flow or both is used to apply a rotational force to a rotatablemember to cause the centrifugal force to be applied to the oil.

In one alternative exemplary embodiment, the electrode arrangements mayinclude a metallic mesh serving as the positive electrode and may beformatted in a spiral wound, pleated, concentric or stacked platearrangement. The positive electrode may also be in the form of aconducting fiber packed into a fixed-bed flow arrangement.Alternatively, the positive electrode may be formed of stainless steel,copper, aluminum, platinum or other electrically conducting material. Inone exemplary embodiment of the present invention, the surface of thepositive electrode has a coating applied, wherein the coating is asoot-collecting agent such as soot particles extracted from lubricatingoil, carbon black from acetylene, soot purchased commercially, activatedcarbon powder, oil-absorbing polymer, other soot-collecting agents or acombination thereof configured to improve the soot-collecting efficiencyon the surface of the positive electrode. In another alternativeembodiment and referring to FIG. 10, the rotating element or member 40in a centrifuge may also serve as the positive electrode, thus combiningelectrostatic with centrifugal separation in a single electro-mechanicaldevice. Alternatively, the rotating element and the positive electrodeare separate items.

In another embodiment, the filtering process is facilitated by filteringthe larger diameter or size soot particles through a filtration media ofthe mechanical filter element, wherein the soot particles are disposedupon a surface of the filtration media. The filtration media being anymedia capable of providing the desired results (e.g., cellulose, nylon,synthetic or equivalents thereof).

Also illustrated in FIG. 10 is a pair of electrodes that are disposed inthe flow path, the electrodes being disposed in the flow path after theinlet but before an exterior filtration surface of the mechanical filterelement 38. In accordance with an exemplary embodiment, the pair ofelectrodes are electrically coupled to an electric current, wherein anelectric field is generated by the pair of electrodes. One of the pairof electrodes is a positive electrode and the electric field causes aportion of the soot particles to agglomerate on the positive electrode.Here, a coating is applied to the surface of the positive electrode,wherein the coating is a soot-collecting agent configured to improve thesoot-collecting efficiency on the surface of the positive electrode. Inorder to remove the agglomerated soot particles at least the positiveelectrode is removable from the filter, wherein the positive electrodeis either removed and replace or cleaned and replaced. It is alsounderstood that the other electrode may also be removable.

In accordance with an exemplary embodiment, the filter may comprise onlythe pair of electrodes with at least one removable electrode.Alternatively, the filter will comprise the pair of electrodes and afiltration media configured to filter the larger diameterpreagglomerated soot particles. In yet another alternative embodiment,the filter will comprise the pair of electrodes and a rotatable elementfor applying a centrifugal force to the preagglomerated soot particlesand a removable surface for collecting the preagglomerated sootparticles. In yet another alternative exemplary embodiment, the rotatingelement and the positive electrode are combined or are one in the same.In still yet another alternative embodiment, the filter will comprisethe pair of electrodes, a filtration media configured to filter thelarger diameter preagglomerated soot particles and a rotatable elementfor applying a centrifugal force to the preagglomerated soot particleshaving a removable surface for collecting the preagglomerated sootparticles.

In accordance with an exemplary embodiment, the lubricating oilcontaining soot is allowed to flow between two electrodes connected toan electric current. Upon application of an electric current, the sootwill collect on the positive electrode to very high levels under certainconditions and electrode arrangements. The electrode arrangements mayinclude a metallic mesh serving as the positive electrode and may beformatted in a spiral wound, pleated, concentric or stacked platearrangement. The positive electrode might also be in the form of aconducting fiber packed into a fixed-bed flow arrangement.Alternatively, the positive electrode may be formed of stainless steel,copper, aluminum, platinum or other electrically conducting material. Inone exemplary embodiment of the present invention, the surface of thepositive electrode has a coating applied, wherein the coating is asoot-collecting agent such as soot particles extracted from lubricatingoil, carbon black from acetylene, soot purchased commercially, activatedcarbon powder, oil-absorbing polymer, other soot-collecting agents or acombination thereof configured to improve the soot-collecting efficiencyon the surface of the positive electrode. The rotating element in acentrifuge may also serve as the positive electrode, thus combiningelectrostatic with centrifugal separation in a single electro-mechanicaldevice. The oil flow to the soot removal device may be either a fullflow or bypass flow with or without further downstream separation.

For example, and as illustrated in FIGS. 11-13A a system of filters maybe employed. As illustrated in FIG. 11 a filter 70 may only comprise thepair of electrodes wherein the unfiltered oil is passed between theelectrodes and soot is agglomerated on the positive electrode and thenthe filtered oil of filter 70 is transferred to another filter 100 (FIG.12) having a centrifuge 40 (with or without a pair of electrodes) tofurther separate the pre-agglomerated oil and thereafter, or as analternative to the filter of FIG. 12 a filter 120 having filter media122 disposed in a filter housing is provided as illustrated in FIG. 13.Thus, a system (FIG. 13A) comprising a first filter 70 (FIG. 11), asecond filter 100 (FIG. 12) and a third filter 120 (FIG. 13) may beprovided. It being understood that the arrows in at least FIGS. 11-13Arepresent fluid flow of an oil between each of the filters, wherein thefluid flow is facilitated by a conduit or other means for transferringthe oil into and out of the filter.

In accordance with an exemplary embodiment of the present invention thefilters may be connected in series or alone as stand alone filters,wherein each of the filters are in fluid communication with each othervia an oil circulation system. For example, the system may comprise onlyone filter (FIG. 11 or 12) or any combinations of the filtersillustrated in FIGS. 11-13. The filters may also comprise a bypassfilter of the system wherein only a portion of the oil is passedtherethrough.

FIG. 14 illustrates one non-limiting exemplary embodiment of a filter 70(e.g., a filter having a pair of electrodes disposed therein). Herefilter 70 has a plurality of inlet openings 72 and at least one outletopening 74. In this embodiment, a center tube 76 defines the at leastone outlet opening wherein the oil flow through filter 70 is illustratedby arrows 34. As illustrated, a bottom portion 78 of the center tube hasopenings to facilitate the oil flow therethrough. In this embodiment,the negative electrode 12 is disposed about the center tube and thepositive electrode 10 disposed in a facing spaced relationship withrespect to the negative electrode 12. In this embodiment, the negativeand positive electrodes comprise closed loops (e.g., circle, oval orother equivalent structures) of electrically conductive materials. Inone non-limiting exemplary embodiment, the eclectically conductivematerials are wire mesh screens or at least the positive electrode is awire mesh screen to facilitate oil flow therethrough. The oil filter 70also has a top end disk 80 and a bottom end disk 82 the bottom end diskbeing proximate to a tapping plate 84 having the inlet and outletopenings. The top end disk is disposed proximate to a top plate 86disposed at an opposite end of the housing. The filter 70 furtherincludes a seal 88 (e.g., rubber, elastomeric or other equivalent typeof material) located on the tapping plate to fluidly seal the tappingplate to a portion of an oil circulation system that the filter is influid communication with. A retainer 90 secures the center tube to thetop end disk and the top plate. As discussed herein, the pair ofelectrodes of the oil filter 70 are electrically coupled to a powersupply 36. Exemplary embodiments contemplate a filter having a removabletop plate wherein the positive electrode is able to be removed andreplaced when the positive electrode has accumulated oil soot thereon.In one embodiment, the positive electrode is simply removed, cleaned andreplaced or the electrode is simply discarded and a new electrode isinserted into the filter by engaging the bottom end disk and the top enddisk, retainer and the top plate are replaced on the filter housing.Alternatively, the oil filter is simply discarded wherein clean or newelectrodes are provided in the new filter.

In any of these embodiments, the power supply is removably secured tothe oil filter to allow removal and replacement of the oil filterwherein the filter itself is simply replaced or the electrodes of thefilter are replaced. In one exemplary embodiment, the power supply iselectrically coupled to a power supply of a vehicle having an enginewith the oil system requiring filtration.

FIGS. 15 and 16 illustrate a non-limiting configuration of a filter 100constructed in accordance with an exemplary embodiment of the presentinvention. Here filter 100 has a housing 102 with an upper housingportion 104 and a lower housing portion 106. The housing having an oilinlet 108 and an oil outlet 110 and a means 112 (e.g., motor 114, shaft116, flow induced rotor 118, an upper bearing 120, a lower bearing 122,an O-ring packing 124, a rotor nut 126 and a washer 128) for rotating acentrifuge rotor 130 having an outer wall 132, a sleeve 136 and a lowerexit rotor 138 for providing a centrifugal force to oil passing throughfilter 100. The upper or lower housing of the filter 100 is removable toallow removal and replacement of the centrifuge when the centrifuge hasaccumulated oil soot thereon. In one embodiment, the centrifuge rotor130 is simply removed, cleaned and replaced or the centrifuge rotor 130is simply discarded and a new centrifuge rotor is inserted into thefilter. In one exemplary embodiment, the centrifuge rotor 130 maycomprise a closed annulus (e.g., circle, oval or other equivalentstructures) of electrically conductive materials. In one non-limitingexemplary embodiment, the electrically conductive materials are wiremesh screens or at least the positive electrode is a wire mesh screen.In yet another non-limiting exemplary embodiment, the positive electrodemay be formed of stainless steel, copper, aluminum, platinum or otherelectrically conducting material. Alternatively; the centrifuge rotor130 may comprise a closed annulus (e.g., circle, oval or otherequivalent structures) of non-conductive materials. Of course, otherconfigurations are considered to be within the scope of exemplaryembodiments of the present invention. Alternatively, the oil filter issimply discarded wherein clean or new centrifuge rotors are provided inthe new filter.

One non-limiting example of a filter similar to filter 100 is found inU.S. patent application Ser. No. 11/626,476 filed Jan. 24, 2007, thecontents of which are incorporated herein by reference thereto. It beingunderstood that this filter may be in series with other filters (e.g.,filter 70 and filter 120) wherein each of the filters are in fluidcommunication with an oil or the components of filter 100 can beincorporated into a filter having a pair of electrodes and in onealternative one of the electrodes may comprise a portion of thecentrifuge of the filter. For example, and as illustrated by the dashedlines in FIG. 15 a power supply may be electrically coupled to thefilter, wherein the centrifuge becomes the positive electrode and thesleeve or shaft becomes the negative electrode.

While the invention has been described with reference to an exemplaryembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims and their legal equivalence.

1. A method for removing soot, sludge and other insoluble particulatesfrom engine oil, the method comprising: disposing an oil containing theparticulates between a pair of electrodes, wherein one of the electrodesis a positive electrode; applying a coating to the surface of thepositive electrode, wherein the coating is configured to collect aportion of the particulates on the positive electrode; applying a directcurrent to the electrodes for a period of time to generate an electricfield, wherein the electric field causes a portion of the particulatesto agglomerate on the positive electrode; and removing the positiveelectrode and the portion of particulates agglomerated on the positiveelectrode to reduce the amount of soot particles in the oil.
 2. Themethod as in claim 1, wherein the particulates are soot particles andthe electric field causes the soot particles to agglomerate resulting ina larger average particle size of the soot particles and the sootparticles are removed by a filtering process.
 3. The method as in claim2, wherein the filtering process comprises application of a centrifugalforce to the oil, wherein the soot particles are disposed upon a surfacethat is removable from the oil.
 4. The method as in claim 3, wherein thesurface is the positive electrode that comprises a portion of a deviceconfigured for applying the centrifugal force.
 5. The method as in claim3, wherein the filtering process comprises filtering of the oil througha filtration media, wherein the soot particles are disposed upon asurface of the filtration media.
 6. The method as in claim 2, whereinthe filtering process comprises filtering of the oil through afiltration media, wherein the soot particles are disposed upon a surfaceof the filtration media.
 7. A method for removing soot from engine oil,the method comprising: disposing an oil containing soot particlesbetween a pair of electrodes; applying a DC or AC current to the pair ofelectrodes for a period of time to generate an electric field, whereinthe electric field causes the soot particles to agglomerate resulting ina larger average particle size of the soot particles; and removing thesoot particles by a filtering process, wherein the filtering processcomprises application of a centrifugal force to the oil, wherein thesoot particles are disposed upon a surface that is removable from theoil.
 8. The method as in claim 7, wherein the filtering processcomprises filtering of the oil through a filtration media, wherein thesoot particles are disposed upon a surface of the filtration media. 9.The method as in claim 7, wherein the filtering process comprisesapplication of a centrifugal force to the oil, wherein the sootparticles are disposed upon a surface that is removable from the oil andthe surface is the positive electrode that comprises a portion of adevice configured for applying the centrifugal force.
 10. The method asin claim 9, wherein the surface of the positive electrode comprises acoating configured to collect a portion of soot particles disposed onthe positive electrode.
 11. A filter for removing soot particles from anengine oil having soot particles disposed therein, the filtercomprising: a housing having an inlet and an outlet defining a flow paththrough a chamber defined by the housing; a pair of electrodes disposedin the flow path, the electrodes being disposed in the flow path afterthe inlet, the pair of electrodes being electrically coupled to a DCcurrent, wherein an electric field is generated by the pair ofelectrodes and one of the pair of electrodes is a positive electrode,wherein the electric field causes a portion of the soot particles toagglomerate on the positive electrode, wherein at least the positiveelectrode is removable from the filter to allow removal of the sootparticles agglomerated on the positive electrode; and a coating appliedto the surface of the positive electrode, wherein the coating isconfigured to improve the collecting efficiency of the agglomeratedportion of soot particles on the positive electrode.
 12. The filter asin claim 11, wherein the positive electrode is formed of stainlesssteel, copper, aluminum, platinum or other electrically conductingmaterial.
 13. The filter as in claim 11, wherein the coating is formedof soot particles extracted from lubricating oil, carbon black fromacetylene, soot purchased commercially, activated carbon powder,oil-absorbing polymer, other soot-collecting agents or a combinationthereof.
 14. The filter as in claim 11, wherein the coating is fixed tothe surface of the positive electrode by adhesive material or the like.15. The filter as in claim 11, wherein the electric field causes thesoot particles to agglomerate resulting in a larger average particlesize of the soot particles and some of the soot particles are removed bya filtering process.
 16. The filter as in claim 15, wherein the filterfurther comprises a rotatable member capable of applying a centrifugalforce to the oil and the filtering process comprises application of acentrifugal force to the oil, wherein some of the soot particles aredisposed upon a surface of the rotatable member that is removable fromthe oil.
 17. The filter as in claim 15, wherein the filtering processfurther comprises filtering of the oil through a filtration media of themechanical filter element, wherein the soot particles are disposed upona surface of the filtration media.